[Internals] Complete notification description for kernel.terminate

Author: bicpi

book/internals.rst

@@ -172,7 +172,10 @@ Event):
 #. Listeners of the ``kernel.response`` event can manipulate the ``Response``
    (content and headers);
 
-#. The Response is returned.
+#. The Response is returned;
+
+#. Listeners of the ``kernel.terminate`` event can perform tasks after the
+   Response has been served.
 
 If an Exception is thrown during processing, the ``kernel.exception`` is
 notified and listeners are given a chance to convert the Exception to a
@@ -367,6 +370,8 @@ The FrameworkBundle registers several listeners:
 ``kernel.terminate`` Event
 ..........................
 
+*Event Class*: :class:`Symfony\\Component\\HttpKernel\\Event\\PostResponseEvent`
+
 The purpose of this event is to perform "heavier" tasks after the response
 was already served to the client.